Just a question as I am not 100% sure myself so I thought I would ask to save myself time trying to figure it out as I'm a little pushed for time to sit & have a look. Got a system was a 500w value PSU, Dual Core AMD cpu, 4gig ddr2, 2 hdd's & a 3780 GPU. Recently I added the second HDD which is a 320gig sata drive. Now this is my grandad's system so that's why it's out dated but anyways. I had a look & the hdd shows up in my computer & is shown up in Device manager list. However, when I try to use Nero to burn a movie to DVD, the hard drive completely vanishes from my system & my gpu display driver stops responding & restarts itself. After this happens, I reboot & the hdd is still missing, but doing a scan in device manager for new hardware it detects it & installs it & it works just perfectly fine then on until I try to transcode the movie with nero before it burns to dvd. Now, Could this be insufficient power from the psu causing the hardware instability or to completely power off? as transcoding movie's to dvd use's the cpu fully & also uses the GPU more which means more power drain. never happens with anything else other than when trying to burn the movie to dvd.